I have a question for the group. I have a new BES900xl and have a question about the pressure (had it for a week). I am consistently getting shot pressures above 9 (11-13). I called Breville and they suggested to "Take the single shot dual wall filter, and place the rubber cleaning disc insert firmly into it- now pull a shot.". I did that and the pressure gauge went to 10 bar and stayed.

Does this sound like an OPV calibration problem? If not, how can the pressure go above 10 bar on a normal espresso extraction?

@MrFolgers- Out of my empiric experience: The pressure of 9 bar is the "official" value where the OPV jumps in (basically as safety measure - in the newest releases of the BES900 machines, the older ones where set to the value you mentioned) and limits pressure. Actually it is imho not a problem at all - could even be a benefit as to have more room to move. It depends how you see this. The OPV can be set to the lower value of 9 bar anytime with minimal effort - thought the machine must be opened and a screw turned a bit.

Point is: You should get your grind and tamping behavior towards that the machine shows you a value of "about" 9 bar while delivering at 93 Celsius in about 25-30 seconds 30 ml tasty espresso for a single shot with the normal one-shot sieve.

MrFolgers Said:

If not, how can the pressure go above 10 bar on a normal espresso extraction?

the OPV does what its name says: The Over Pressure Valve jumps in after the shot, to release the pressure within the grouphead safely, opens and direct the not- anymore-needed water(pressure) towards the drip-tray, as well to secure that the used coffeepowder is, when the grouphead is disengaged, not (like on the Pavoni) painting your kitchen brown.

But even 10 bar or 13 bar are not a technical problem - probably except for the taste :-)

Clear Water Back-flush as above, then1/2 scoop caffeto or similar into blind filterinsert into group headpress & hold 2 cup button for 60secsallow to "soak" for 60secspress & hold 2 cup button for 10 secs, repeat 4-5 timesrepeat clear water back-flushsoak PF (head only, not the handle) in solution of Caffeto & hot water for 10mins, rinse after

if you limit the individual back-flush under the "magic" 7 seconds, then the shot is intern not as such registered - towards the 6.000 accumulated shots after that the machine has to be send in for descaling.

When I started shopping around for a new espresso maker I initially wanted a machine that just required me to put a cup under the spout, push a button and then receive liquid magic. Unfortunately, the internet said: you can do that, but that magic you will receive will be mediocre at best. bummers. Continued research brought me to this strange thing called Latte Art which highlighted the need for a machine capable of producing massive amounts of 'dry' steam. Which brought me to the Breville Dual Boiler. I did a ton of research was pretty much sold on the this unit. There are perhaps better units for a higher price, but none of the cheaper units appeared to be as capable. IE - the value of the machine was in the sweet spot for me.

I ordered the machine itself from Amazon b/c I'm impatient and wanted it now! You can't beat $3.99 for overnight shipping (I'm a AP subscriber). The machine arrived on Tuesday. If I was still buying my lattes at Starbucks I'd be ought several hundred dollars by now (2 full days later). I'm really very happy with the machine and what it came with. It's really easy to operate and the user's manual it comes with is really well written and useful. I had the time set and the auto-on feature setup in about 30 seconds. I get up at ~5:30am, it's nice to walk in to the kitchen and see those lights already glowing and waiting for me.

Unfortunately, my new grinder has not arrived so I'm still using my old Capresso grinder. I've ordered a smart grinder from Seattle Coffee Gear b/c their videos played a big role in me buying the machine. I would have bought the machine from them, but as I mentioned: I wanted my Umpa Lumpa now! So I ordered the accessories from them and will order other stuff as well.

Anyway - despite whatever real or imagined deficiencies my grinder has I'm able to get a decent shot from the unit as long as I tamp the grind down hard. I know the shot isn't quite right because the shot is brewed in under 20 seconds, but the pressure is up around 9bar and the flavor is pretty good. I'd put my shot up against Starbucks (I realize Starbucks is not respected but for 99% of the population it's what they know) but not against the nicer restaurants I go to.

Based on what I've read in this thread I'll start weighing my espresso before tamping it. I'll also experiment with different grinds to see if they help. I'd like to get to 30 seconds total time from first drip to full 2oz shot.

For coffee I'm getting freshly roast beans from Addison Coffee Company (they're a short drive from my house and just up the street from my practice's office). Right now I'm using their premium espresso which was roasted last Friday (ie - it's fresh).

I'm also going to look around and see if I can find somebody to show me how it's done. Maybe somebody in the Dallas area can point me in the right direction?

I work from home most of the time and really enjoy good coffee. Not having to leave the house (Starbucks) would be pretty freaking cewl. I'd eventually like to be able to do some of the cool parlor tricks like latte art, but I'll be happy just making a really great tasting cup of espresso.

Anyway - despite whatever real or imagined deficiencies my grinder has I'm able to get a decent shot from the unit as long as I tamp the grind down hard. I know the shot isn't quite right because the shot is brewed in under 20 seconds, but the pressure is up around 9bar and the flavor is pretty good.

@RaymondParker - Thanks. I'll see if I can get the capresso grinder down further but I think it is down about as far as it will go. The new unit arrives next Tuesday so I'll survive until then.

I should have mentioned the downside to have this infernal new machine in the house: When Thanksgiving dinner was served I was actually too frigging full of espresso and microfoam to eat much. On the bright side I'll have plenty of room for a nice cappuccino and pumpkin pie in a little while.

the OPV does what its name says: The Over Pressure Valve jumps in after the shot, to release the pressure within the grouphead safely, opens and direct the not- anymore-needed water(pressure) towards the drip-tray, as well to secure that the used coffeepowder is, when the grouphead is disengaged, not (like on the Pavoni) painting your kitchen brown.

But even 10 bar or 13 bar are not a technical problem - probably except for the taste :-)

Actually, the name OPV is a misnomer as well. The correct name is PRV (Pressure Regulating Valve). It works by opening and releasing pressure at a set point (9 bar is the most common setting). You can grind finer, but the pressure will never exceeed 9 bar. All the will happen is that the flow will slow or stop completely.

Symbols: = New Posts since your last visit = No New Posts since last visit = Newest post

Forum Rules:No profanity, illegal acts or personal attacks will be tolerated in these discussion boards.No commercial posting of any nature will be tolerated; only private sales by private individuals, in the "Buy and Sell" forum.No SEO style postings will be tolerated. SEO related posts will result in immediate ban from CoffeeGeek.No cross posting allowed - do not post your topic to more than one forum, nor repost a topic to the same forum.Who Can Read The Forum? Anyone can read posts in these discussion boards.Who Can Post New Topics? Any registered CoffeeGeek member can post new topics.Who Can Post Replies? Any registered CoffeeGeek member can post replies.Can Photos be posted? Anyone can post photos in their new topics or replies.Who can change or delete posts? Any CoffeeGeek member can edit their own posts. Only moderators can delete posts.Probationary Period: If you are a new signup for CoffeeGeek, you cannot promote, endorse, criticise or otherwise post an unsolicited endorsement for any company, product or service in your first five postings.